"Samantha and I just got assaulted by the security," Hynes tweeted after the show. "They grabbed her," he said in a subsequent Tweet. "I asked what they were doing and they grabbed my neck and threw me to the ground, then two others joined in on me."

Late Saturday evening police received a battery complaint involving private security staff not employed by the venue, battery of an entertainer and a female friend. No one is in custody and no one was injured. The victims were a male 28 and a female, 26.

Officer Amina Greer, of Police News Affairs, says that the security guards in question are not employed by Lollapalooza.

Hynes' publicist said the singer would have no further comment at this time.

A Lollapalooza spokesman also offered no further information beyond pointing to a statement issued late Friday by promoters C3 Presents: "Late Friday night, we learned of an incident involving an artist and a security guard on site, Since then, we have been in contact with those involved and the authorities, as we work together to resolve the situation. As always, our top priority is to ensure the safety of everyone at the festival."